Flat items, such as packaging blanks, paper sheets, inserts, mailing packets, etc., are often fed one at a time from a stack to apparatus for further processing. In many applications, it is necessary that the flat items be delivered to register with the timed operation of the apparatus.
A variety of feeding apparatus have been employed in the packaging industry including combing wheel feeders, reciprocating vacuum feeders, such as that described for right angled feed in U.S. Pat. No. 2,449,690, bump feeders, such as that described in U.S. Pat. No. 3,406,963 in which a stack is alternately lifted from and lowered onto a feed belt in order to feed articles one-by-one from the bottom of the stack, and rotary placers. All of the feed systems used have certain disadvantages. Some feeder designs are inherently limited in speed and unnecessarily slow down the entire processing line. Some require such precise adjustment that very skilled operators are needed to run the feeders. Those which feed from the top of a stack may be difficult to load. Some may be very difficult to adjust to accommodate various size articles. Bump feeders lack positive engagement of the apparatus with the article, a drawback particularly disadvantageous when feeding articles with slick coatings or articles with ridges or scorelines which tend to interlock. The bending of the articles by right angle feeders is undesirable in many applications.
The need exists for improved flat article feeders which positively engage articles and discharge them one-by-one in a precise manner.